In such a regenerator, the hot gases and cold gases are respectively conveyed radially through the heat accumulation mass, in contrast to air heaters which are otherwise usual, and actually during the heating phase, from the hot collection chamber inside the regenerator to the outer cold collection chamber, and in the opposite direction during the cold blowing of the regenerator. The gases to be heated may also be gaseous mixtures, which also contain proportions of vapors, in particular water vapor.
A regenerator of this type is described in U.S. Pat. No. 2,272,108. The quantitative embodiment, not given here, of the example of application which is given therein shows that a regenerator according to the description of this U.S. Patent would absolutely not operate in practice. A qualitative evaluation furthermore demonstrates that the gas speed chosen for passing through the heat accumulation layer was chosen much too small and furthermore that the aforementioned size of the particles of the loose bulk material of the heat accumulation mass is too large. These values thus lead to a head loss of the gas which is too small in the material bed. Thus, the pressure of the gas decreases with the height in the cold collection chamber, while this effect, also known by the term "stack effect", is negligible in the cold collection chamber. In the application example, the pressure difference caused by this "stack effect" is a multiple of the head loss in the material bed, with the consequence that, when heating the regenerator, the heating gases flow only in the upper region through the material bed while, in the lower region, back-flow might even be expected. When working under hot blast, and therefore during the cold blowing, the conditions are reversed, that is to say that only the lower region of the material bed would be exposed. These results necessarily lead to the conclusion that the regenerator described in U.S. Pat. No. 2,272,108 would fail entirely.